TY  - JOUR
A1  - Maggakis-Kelemen, Christina
A1  - Digel, Ilya
A1  - Artmann, Gerhard
T1  - Polystyrene sulfonate/Polyallylamine hydrochloride microcapsules as potential artificial red blood cells - improvement of capsule flexibility
JF  - Biomedizinische Technik. 50 (2005), H. Erg.-Bd. 1
Y1  - 2005
SP  - 324
EP  - 326
ER  - 
TY  - JOUR
A1  - Khodaverdi, M.
A1  - Chatziioannou, A. F.
A1  - Weber, S.
A1  - Ziemons, Karl
A1  - Halling, H.
A1  - Pietrzyk, U.
T1  - Investigation of different MicroCT scanner configurations by GEANT4 simulations
JF  - IEEE Transactions on Nuclear Science
N2  - This study has been performed to design the combination of the new ClearPET (ClearPET is a trademark of the Crystal Clear Collaboration), a small animal positron emission tomography (PET) system, with a micro-computed tomography (microCT) scanner. The properties of different microCT systems have been determined by simulations based on GEANT4. We will demonstrate the influence of the detector material and the X-ray spectrum on the obtained contrast. Four different detector materials (selenium, cadmium zinc telluride, cesium iodide and gadolinium oxysulfide) and two X-ray spectra (a molybdenum and a tungsten source) have been considered. The spectra have also been modified by aluminum filters of varying thickness. The contrast between different tissue types (water, air, brain, bone and fat) has been simulated by using a suitable phantom. The results indicate the possibility to improve the image contrast in microCT by an optimized combination of the X-ray source and detector material.
Y1  - 2005
SN  - 0018-9499
VL  - 52
IS  - 1
SP  - 188
EP  - 192
ER  - 
TY  - JOUR
A1  - Streun, M.
A1  - Christ, D.
A1  - Hellendung, A.
A1  - Larue, H.
A1  - Ziemons, Karl
A1  - Halling, H.
T1  - Effects of crosstalk and gain nonuniformity using multichannel PMTs in the Clearpet® scanner
JF  - Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment
N2  - The ClearPET® scanners developed by the Crystal Clear Collaboration use multichannel PMTs as photodetectors with scintillator pixels coupled individually to each channel. In order to localize an event each channel anode is connected to a comparator that triggers when the anode signal exceeds a common predefined threshold. Two major difficulties here are crosstalk of light and the gain nonuniformity of the PMT channels. Crosstalk can generate false triggering in channels adjacent to the actual event. On the one hand this can be suppressed by sufficiently increasing the threshold, but on the other hand a threshold too high can already prevent valid events on the lower gain channels from being detected. Finally, both effects restrict the dynamic range of pulse heights that can be processed. The requirements to the dynamic range are not low as the ClearPET® scanners detect the depth of interaction by phoswich pixels consisting of LSO and Lu0.7Y0.3AP, two scintillators with different light yields. We will present a model to estimate the achievable dynamic range and show solutions to increase it.
Y1  - 2005
SN  - 0168-9002
N1  - Proceedings of the 7th International Conference on Inorganic Scintillators and their Use in Scientific and Industrial Applications
VL  - 537
IS  - 1-2
SP  - 402
EP  - 405
ER  - 
TY  - JOUR
A1  - Ziemons, Karl
A1  - Auffray, E.
A1  - Barbier, R.
A1  - Brandenburg, G.
A1  - Bruyndonckx, P.
T1  - The ClearPET™ project: Development of a 2nd generation high-performance small animal PET scanner
JF  - Nuclear Instruments and Methods in Physics Research, Section A: Accelerators, Spectrometers, Detectors and Associated Equipment
N2  - Second generation high-performance PET scanners, called ClearPET™1, have been developed by working groups of the Crystal Clear Collaboration (CCC). High sensitivity and high spatial resolution for the ClearPET camera is achieved by using a phoswich arrangement combining two different types of lutetium-based scintillator materials: LSO from CTI and LuYAP:Ce from the CCC (ISTC project). In a first ClearPET prototype, phoswich arrangements of 8×8 crystals of 2×2×10 mm3 are coupled to multi-channel photomultiplier tubes (Hamamatsu R7600). A unit of four PMTs arranged in-line represents one of 20 sectors of the ring design. The opening diameter of the ring is 120 mm, the axial detector length is 110 mm.The PMT pulses are digitized by free-running ADCs and digital data processing determines the gamma energy, the phoswich layer and even the exact pulse starting time, which is subsequently used for coincidence detection. The gantry allows rotation of the detector modules around the field of view.

Preliminary data shows a correct identification of the crystal layer about (98±1)%. Typically the energy resolution is (23.3±0.5)% for the luyap layer and (15.4±0.4)% for the lso layer. early studies showed the timing resolution of 2 ns FWHM and 4.8 ns FWTM. the intrinsic spatial resolution ranges from 1.37 mm to 1.61 mm full-width of half-maximum (FWHM) with a mean of 1.48 mm FWHM. further improvements in image and energy resolution are expected when the system geometry is fully modeled.
Y1  - 2005
SN  - 0168-9002
N1  - Proceedings of the 7th International Conference on Inorganic Scintillators and their Use in Scientific and Industrial Applications
VL  - 537
IS  - 1-2
SP  - 307
EP  - 311
ER  - 
TY  - JOUR
A1  - Grajewski, Matthias
A1  - Hron, Jaroslav
A1  - Turek, Stefan
T1  - Dual weighted a posteriori error estimation for a new nonconforming linear finite element on quadrilaterals
JF  - Applied Numerical Mathematics
N2  - After a short introduction of a new nonconforming linear finite element on quadrilaterals recently developed by Park, we derive a dual weighted residual-based a posteriori error estimator (in the sense of Becker and Rannacher) for this finite element. By computing a corresponding dual solution we estimate the error with respect to a given target error functional. The reliability and efficiency of this estimator is analyzed in several numerical experiments.
Y1  - 2005
U6  - http://dx.doi.org/10.1016/j.apnum.2004.09.016
SN  - 0168-9274
VL  - 54
IS  - 3-4
SP  - 504
EP  - 518
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - JOUR
A1  - Staat, Manfred
T1  - Plastic collapse analysis of longitudinally flawed pipes and vessels
JF  - Nuclear Engineering and Design. 234 (2004), H. 1-3
Y1  - 2004
SN  - 0029-5493
SP  - 25
EP  - 43
ER  - 
TY  - JOUR
A1  - Staat, Manfred
A1  - Kühn, R.
A1  - Hauger, W.
A1  - Sponagel, Stefan
T1  - An Interpretation of Wolff’s Law
JF  - Biomedizinische Technik. 49 (2004)
Y1  - 2004
SN  - 0932-4666
N1  - Ergänzungsband 2, Teil 2
SP  - 1020
EP  - 1021
ER  - 
TY  - JOUR
A1  - Staat, Manfred
A1  - Vu, Duc-Khoi
T1  - An Algorithm for Shakedown Analysis for Materials with Temperature Dependent Yield Stress
JF  - Proceedings in Applied Mathematics and Mechanics (PAMM). 4 (2004), H. 1
Y1  - 2004
SN  - 1617-7061
SP  - 231
EP  - 233
ER  - 
TY  - JOUR
A1  - Poghossian, Arshak
A1  - Schöning, Michael Josef
T1  - Detecting Both Physical and (Bio-)Chemical Parameters by Means of ISFET Devices
JF  - Electroanalysis. 16 (2004), H. 22
Y1  - 2004
SN  - 1040-0397
SP  - 1863
EP  - 1872
ER  - 
TY  - JOUR
A1  - Poghossian, Arshak
A1  - Mai, D.-T.
A1  - Mourzina, Y.
A1  - Schöning, Michael Josef
T1  - Impedance effect of an ion-sensitive membrane: characterisation of an EMIS sensor by impedance spectroscopy, capacitance-voltage and constant-capacitance method
JF  - Sensors and Actuators B. 103 (2004), H. 1-2
Y1  - 2004
SN  - 0925-4005
SP  - 423
EP  - 428
ER  - 
TY  - JOUR
A1  - Schöning, Michael Josef
A1  - Kloock, Joachim P.
T1  - Labor für Chemo- und Biosensorik an der FH Aachen, Abt. Jülich – Mehr als nur studieren
JF  - Fachblatt Fachhochschule Aachen (2004)
Y1  - 2004
SN  - 1430-7707
SP  - 18
EP  - 19
ER  - 
TY  - JOUR
A1  - Kloock, Joachim P.
A1  - Mourzina, Y.G.
A1  - Ermolenko, Y.
A1  - Doll, T.
A1  - Schubert, J.
A1  - Schöning, Michael Josef
T1  - Inorganic thin-film sensor membranes with PLD-prepared chalcogenide glasses: Challenges and implementation
JF  - Sensors. 4 (2004), H. 10
Y1  - 2004
SN  - 1424-8220
SP  - 156
EP  - 162
ER  - 
TY  - JOUR
A1  - Yoshinobu, T.
A1  - Schöning, Michael Josef
A1  - Finger, F.
A1  - Moritz, W.
A1  - Iwasaki, H.
T1  - Fabrication of thin-film LAPS with amorphous silicon
JF  - Sensors. 4 (2004), H. 10
Y1  - 2004
SN  - 1424-8220
SP  - 163
EP  - 169
ER  - 
TY  - JOUR
A1  - Poghossian, Arshak
A1  - Ingebrandt, S.
A1  - Yeung, C.-K.
A1  - Offenhäusser, A.
A1  - Schöning, Michael Josef
T1  - Microsensors based on ion-sensitive field-effect transistors for biomedical applications
JF  - Biomedizinische Technik. 49 (2004), H. 2
Y1  - 2004
SN  - 0932-4666
SP  - 1036
EP  - 1037
ER  - 
TY  - JOUR
A1  - Kassab, T.
A1  - Han, Y.
A1  - Poghossian, Arshak
A1  - Ingebrandt, S.
A1  - Offenhäusser, A.
A1  - Schöning, Michael Josef
T1  - Detection of layerby-layer adsorbed polyelectrolytes by means of field-effect based capacitive EIS structures
JF  - Biomedizinische Technik. 49 (2004), H. 2
Y1  - 2004
SN  - 0932-4666
SP  - 1034
EP  - 1035
ER  - 
TY  - JOUR
A1  - Moritz, W.
A1  - Yoshinobu, T.
A1  - Finger, F.
A1  - Krause, S.
A1  - Xu, M.
A1  - Schöning, Michael Josef
T1  - Microscopy of impedance and surface ion concentrations
JF  - Biomedizinische Technik. 49 (2004), H. 2
Y1  - 2004
SN  - 0932-4666
SP  - 1000
EP  - 1001
ER  - 
TY  - JOUR
A1  - Ermolenko, Y. E.
A1  - Yoshinobu, T.
A1  - Mourzina, Y. G.
A1  - Vlasov, Y. G.
A1  - Schöning, Michael Josef
A1  - Iwasaki, H.
T1  - Laserscanned transducer (LSST) as a multisensor system
JF  - Sensors and Actuators B. 103 (2004), H. 1-2
Y1  - 2004
SN  - 0925-4005
SP  - 457
EP  - 462
ER  - 
TY  - JOUR
A1  - Yoshinobu, T.
A1  - Ui, Y.
A1  - Iwasaki, H.
A1  - Näther, Niko
A1  - Koudelka-Hep, M.
A1  - Schöning, Michael Josef
T1  - Potentiometric imaging in a microfluidic channel
JF  - Biomedizinische Technik. 49 (2004), H. 2
Y1  - 2004
SN  - 0932-4666
SP  - 998
EP  - 999
ER  - 
TY  - JOUR
A1  - Wagner, Torsten
A1  - Schöning, Michael Josef
A1  - Otto, R.
A1  - Yoshinobu, T.
T1  - A handheld 16 channel pen-type LAPS as a platform for (bio-)electrochemical sensing
JF  - Biomedizinische Technik. 49 (2004), H. 2
Y1  - 2004
SN  - 0932-4666
SP  - 996
EP  - 997
ER  - 
TY  - JOUR
A1  - Näther, Niko
A1  - Auger, V.
A1  - Poghossian, Arshak
A1  - Koudelka-Hep, M.
A1  - Schöning, Michael Josef
T1  - A miniaturized flow-through cell in SU-8 technique for EIS sensors
JF  - Biomedizinische Technik. 49 (2004), H. 2
Y1  - 2004
SN  - 0932-4666
SP  - 994
EP  - 995
ER  -